In recent years, it has been revealed that the propagation characteristics of electromagnetic waves is controlled by periodic arrangement of conductor patterns having a specific structure (hereinafter, called a meta-material). For example, the use of a meta-material enables a reduction in size and thickness of an antenna.
Examples of related art relevant to a meta-material include techniques disclosed in Patent Documents 1 and 2. A technique disclosed in Patent Document 1 relates to a structure, or a so-called mushroom-type meta-material in which a plurality of insular conductor patterns are disposed above sheet-like conductor patterns, and each of the insular conductor patterns is connected to a sheet-like conductor pattern through a via.
A technique disclosed in Patent Document 2 provides a layer including a second auxiliary conductor pattern between a layer in which insular conductor patterns are formed and a layer in which sheet-like conductor patterns are formed, in a mushroom-type meta-material. The second auxiliary conductor pattern is formed so as to fill the gaps between the insular conductor patterns in a plan view, and is not connected to any of the insular conductor pattern and the sheet-like conductor patterns.